The present invention relates to a connection system for a hot gas-conducting annular duct of a turbine intermediate casing of a gas turbine, in particular an aircraft gas turbine, including a first housing element, in particular a panel of a turbine intermediate casing, a second housing element, in particular a fairing of a turbine intermediate casing, which is situated next to the first housing element in the circumferential direction, a fastening unit which is configured for connecting the first housing element and the second housing element to one another at edges of the first housing element and of the second housing element, which are adjacent to one another in the circumferential direction, the fastening unit including a clamping element which is mounted on the one housing element with the aid of a connection means, in particular a bolt-nut connection, the clamping element resting on a clamping surface provided on the other housing element in such a way that the other housing element is accommodated between the clamping element and the one housing element. Such a connection system is known, for example, from U.S. Pat. No. 5,451,116 A.
It is pointed out that directional information such as “axial”, “radial”, and “circumferential” are intended to be understood to relate, in principle, to the machine axis of the gas turbine, as long as nothing else results, explicitly or implicitly, from the context.
A turbine intermediate casing (turbine center frame or TCF), in particular its portion which delimits the hot gas duct, typically includes a plurality of housing elements which may be referred to as panels and fairings (for the aerodynamic encasing of the struts). These housing elements are connected to one another with the aid of bolted/clamping connections, so-called “dorito connections.” The housing elements or fairings and panels, together, define the annular gas duct for conducting the hot gas from the high-pressure turbine into the low-pressure turbine. Such a design based on clamping is selected in order allow for thermally induced relative motions, within certain limits, between the fairings and panels when the gas turbine transitions from one operating state into another operating state, without generating impermissibly high stresses in the fairings and panels.